1. Field of the Invention
The invention relates generally to apparatus for treating surfaces of wafer-shaped articles, such as semiconductor wafers, and more particularly for collector structures for use with such apparatus.
2. Description of Related Art
Semiconductor wafers are subjected to various surface treatment processes such as etching, cleaning, polishing and material deposition. To accommodate such processes, a single wafer may be supported in relation to one or more treatment fluid nozzles by a chuck associated with a rotatable carrier. Such chucks are often equipped with a surrounding collector for gathering used liquids and exhaust gases generated by the processes. Examples of such collectors are shown in FIG. 3 of U.S. Pat. No. 4,903,717 and U.S. Pat. No. 7,837,803.
These collectors include a plurality of process levels, which in practice is most commonly three. The spin chuck can be moved relative to the collector between each of these three process levels, as well as to an uppermost loading and unloading position.
However, in some cases only one or two processing compositions are utilized for a given spin chuck, in which case not all of the three levels are used. Furthermore, in the conventional collector designs, cleaning and repair of any part of the collector would place the entire collector out of service.